Update fonts from MathJax

Summary:
Also, rename all of our uses of fonts to use the uppercased versions. We want to
use the uppercase versions because it makes updating and modifying the fonts
much easier (since the font names inside the actual font files are uppercased).

Test Plan:
  - Make sure the huxley screenshots look good (You can compare a diff of them
    on github at
    f90d093361
    By my eye, it seems like some things have moved up ~1/2 pixel, and some of
    the fonts have maybe slightly changed shape, like the large `b` in
    SizingBaseline)

Reviewers: alpert

Reviewed By: alpert

Differential Revision: http://phabricator.khanacademy.org/D11979

dockers/MathJaxFonts/README.md

@@ -0,0 +1,66 @@
+### How to generate MathJax fonts
+-----------------------------
+
+It's really simple (now)! Just make a docker image from the included Dockerfile
+using a command like
+
+  sudo docker build --tag=mathjaxfonts .
+
+from within this directory (note you need to have docker installed and running
+for this to work). This will build a docker image with the mathjaxfonts tag,
+which you can then use to run dockers based on them. Then, run a mathjaxfonts
+docker with
+
+  sudo docker run --interactive --tty mathjaxfonts --name mjf /bin/bash
+
+We name this docker "mjf" so we can reference it later when we want to copy the
+files off. (If you get an error about the name being in use, perhaps because you
+are trying to create another docker, you can either delete the old docker with
+
+  sudo docker rm mjf
+
+or use a different name.) This will get you into the docker in the root
+directory. From there, cd into the `/MathJax-dev/fonts/OTF/TeX` directory, and
+run
+
+  make ttf eot woff
+
+to build all of the fonts that we need. Finally, leave the docker and copy all
+the files off with
+
+  docker cp mjf:/MathJax-dev/fonts/OTF/TeX/ttf ./
+  docker cp mjf:/MathJax-dev/fonts/OTF/TeX/eot ./
+  docker cp mjf:/MathJax-dev/fonts/OTF/TeX/woff ./
+
+(note we're using `mjf:` to specify the name of the docker we created above)
+Compile the fonts into a single directory
+
+  mv {ttf,eot,woff}/* ./
+
+Remove the WinIE6 and WinChrome fonts
+
+  rm KaTeX_Win*
+
+And you're good to go! Don't forget to update the font metrics with the
+metric_parse.rb script once you're done.
+
+### General Docker Help
+-----------------------
+
+When you quit the docker, it will stop the docker from running. If you want to
+reattach to the docker, you can start it again with
+
+  sudo docker start mjf
+
+and then attach with
+
+  sudo docker attach mjf
+
+Alternatively, if you want to detach from the docker when you're done instead of
+quitting and stopping it, you can detach with `C-p C-q`, and then re-attach with
+
+  sudo docker attach mjf
+
+To see a list of your current dockers, you can run
+
+  docker ps